Please tell me how you have calculated differece of time 2 days.
Sundar said:
(Mon, Jul 5, 2010 07:59:13 AM)
Hi Friends!
The statement "A is thrice as good as workman as B" states that, If A complete a work in 1 day, B will take 3 days to complete the same work.
Therefore, if A takes 1 day, B takes 3 days, the time difference is 2 days.
If the time difference is 2 days, B takes 3 days to complete the work.
Similarly if the time difference is 60 days, then B takes (3/2*60) = 90 days.
Then A takes 90 - 60 = 30 days to complete the work.
It is very simple man.
Kumar said:
(Mon, Jul 5, 2010 08:21:34 AM)
Hi Guys,
Let me do the same thing with different values.
Given statement : "A is thrice as good as workman as B"
Time difference : 60 days.
If B takes 12 days to complete a work, A will take only 4 days to complete the same work.
So, B takes 12 days whereas A takes 4 days only (because A is thrice as good as B).
Here time difference is 12 - 4 = 8 days.
If the time difference is 8 days, B takes 12 days.
Similarly if the time difference is 60 days, then B takes (12/8 * 60) = 90 days.
...Rest thing you can understand from the explanation part.
Bharathi said:
(Fri, Jul 9, 2010 08:17:23 AM)
Dear Friends,
In this question atlast we got (a+b)'s 1 day work=2/45.
How it is changed to be an A and B are together can do the work in 45/2.
Nagu said:
(Mon, Jul 12, 2010 02:55:48 AM)
Hi Bharathi,
If A takes 10 days to complete a work means
A's one day work is 1/10
so complete this work A takes 10/1 days is same as 10 days
Sat the same way (A + B)'s 1 day's work 2/45 means
They will take 45/2 = 22 1/2 days
I think you got my point
have a nice day
Sheetal said:
(Tue, Aug 3, 2010 05:55:57 AM)
Hi Guys,
Don't be confused in data given in question.
I have one short cut to solve such kind of question.
A is K times as good a worker as B & takes X days less than B to finish the work. Then the amount of time required by A & B working together is K * X / K'S SQUARE - 1.
SO IN QUESTION K IS 3. X IS 60. SO PUTTING THE VALUES IN ABOVE MENTIONED FORMULA.
K * X / K'S SQUARE - 1
=3 * 60 / 9 - 1
=3 * 60 / 8
=180 / 8
=22.5 DAYS
AS MENTIONED OPTION B.
I HOPE U WILL UNDERSTAND THIS THING & WILL APPLY IN QUESTION BASED ON THIS.
All the best. Have nice day!
Sangeetha said:
(Wed, Aug 4, 2010 05:01:40 AM)
Oh thanks sheetal
Indhu said:
(Wed, Sep 1, 2010 01:31:37 PM)
Hi friends,.
Though content is big it is easy to understand.
Work done by A as compared to B=3:1.
Time taken by A as compared to B=1:3.
So, time difference is 2.
A will finish the work 60 days lesser than B.
Therefore time difference is 60.
Time taken for A = 60/2 = 30.
Hence time taken for B=3* time taken by A = 90.
If A+B can do a piece of work in n days, then (A+B) 's 1day's work=1/n.
Working together (A+B) 's one day work = (1/30) + (1/90) =2/45.
If (A+B) 's 1day's work=1/n, then A+B can finish the work in n days.
Therefore total time taken = 45/2= 22. 5 Days.
Prashant said:
(Wed, Sep 15, 2010 12:25:09 AM)
Suppose B takes x days to finish the work and then according to question A will take (60-x) days to work. in question the ratio of time taken is 1:3 therefore
1/3= (60-x)/x
x=45
So A can complete the work in (60-x)=(60-45)=15 days
So (A+B) one day's work
=(1/15 + 1/45)
=4/45
So (A+B) complete the work in 45/4 = 11 1/4 days.
Sugumaran said:
(Wed, Sep 22, 2010 12:02:06 AM)
Ratio of time taken=1:3
A finish the work in 60 days and B in x days.
1:3::60:x
x=180 days
So,
A and B 1'days work 1/60+1/180=45 days
Is it correct or not?
M.Atul said:
(Thu, Sep 23, 2010 05:54:37 AM)
@Sugumaran please read carrefully problem. Though you have got same answer but it doesn't satisfied second condition that differnce in day should be 60 not 120.
Priya said:
(Thu, Sep 23, 2010 11:58:14 AM)
Please tell me why we are taking 3/2 to multiply with 60. Please explin me.
Harsha said:
(Wed, Oct 13, 2010 08:29:53 AM)
A clear approach:
Given: A's time taken:B's time taken=1:3
So A's proportion of time taken=1/(1+3)=>1/4*some x
B's proportion of time taken=3/(1+3)=>3/4*some x
As it is said that difference of time is 60 days
B's time-A's time=60
=> 3x/4-x/4=60
=>x=120
So A's proportion of time taken =x/4=120/4=30 days
B's proportion of time taken =3x/4=3*120/4=90 days
A's 1 day's work = 1/30
B's 1 day's work = 1/90
(A + B)'s 1 day's work = (1/30 + 1/90)= 4/90=2/45
A and B together can do the work in 45/2 = 22 1/2 days.
Naveen said:
(Tue, Oct 26, 2010 09:37:38 AM)
Hi, in prashanth answer, he equals the ratio 1/3 to 60-x/x but it actually x-60/x.
Shilpi said:
(Thu, Nov 18, 2010 09:18:05 AM)
Can you pls teach me this equation
1/30+1/90=4/90
Ashirwad said:
(Sat, Nov 27, 2010 04:49:49 PM)
HI FRIENDS THIS IS THE simplest method for solving this type of que....
K*S/(A^2-1)
where S=DAYS FOR FINISHING WORK(60 GIVEN IN QUE)
K=3 GIVEN IN QUE
Ashirwad Dubey said:
(Sun, Nov 28, 2010 02:48:59 PM)
Hi friends
k*x/(k^2-1)
k=3
x=60 given in que
ok friends
Vikas said:
(Wed, Dec 29, 2010 10:08:25 AM)
I didnt understand how did we get that (3/2)*60 ?
Showry said:
(Wed, Jan 5, 2011 02:10:11 AM)
Hi Friends,
A:B=1:3 time taken.........since A is 3 good as B
A takes 60 days less than B
B-60:B=1:3............
i.e B-60/B=1/3..... B=90 days.... A=30......
(A+B)'s one day work (1/30+1/90) = (2/45)
Total work by (A+B) is 45/2 i.e 22 1/2.............
Gowri said:
(Sat, Jan 8, 2011 05:34:53 AM)
kl/(k)^2-1
k=3
l=60
3*60/(3)^2-1
=45/2
=22.5
Nagarjun said:
(Thu, Jan 13, 2011 11:46:43 PM)
@Vikas
Its just cross multiplication.
If the difference is 2 days then b takes 3 days
If the difference is 60 days then b takes x days
Hence, x= (60*3)/2.
I think you got it now.
Naresh Kumar said:
(Tue, Jan 18, 2011 04:11:52 AM)
Thank you guys.
Malini said:
(Wed, Jan 19, 2011 07:49:13 AM)
Sheetal thanks a lot dear. This short cut is very much easy.
Baskar said:
(Fri, Jan 21, 2011 12:29:40 AM)
@bharathi
i think u r in confusion..
just know dat
work = day..
1 day = 2/45 works..
in ques ask abt "work"?
den cross mul
1 work = 45/2 days..
now u got it
G.P. said:
(Thu, Feb 10, 2011 04:32:14 AM)
SIMPLE AND BEST WAY
since a is thrice better than b
hence a:b=1:3
similarly a takes 60 days less than b
hence a:b=(b-60):b=1;3
cross multiplication n we get
3b-180=b hence b=90days hence a=30days
1/90+1/60=4/90 hence total daysreciprocal 90/4=45/2
Nishant said:
(Thu, Feb 10, 2011 11:53:34 AM)
@ G.P.
Thanks. I like the way you solve it.
Balaji said:
(Sat, Feb 19, 2011 12:11:16 AM)
Showry you explained superbly.
Prathyusha said:
(Mon, Feb 28, 2011 08:30:19 PM)
SIMPLE AND NICE EXPLANATION!... @KUMAR
Vani said:
(Fri, Mar 18, 2011 10:30:40 PM)
Showry's explanation is good.
Siva said:
(Thu, Apr 21, 2011 01:38:29 PM)
Hi Guys,
I think following simple method (alternate) will make you more clear,
A can complete work in N days => A's 1day work = (1/N)----1
B can complete work in n days => B's 1day work = (1/n)----2
Given data,
A thrice as B so , A=3B
A complete work 60 days less than B so, (N=n-60)
Apply in 1 & 2
A's 1day work = (1/(n-60))-----3
B's 1day work = (1/n)--------4
we know that A=3B ; B=(1/n) so,Apply B in A we get[A=3/n]
Apply in 3
3/n=(1/(n-60))
by solving,
3n-180=n
n=90
so, B can complete work in 90 Days => B's 1 Day work =(1/90)
we know that N=n-60,
so, A can complete work in 30 Days => A's 1 Day work = (1/30)
(A+B) 1 Day work = (1/30 + 1/90)
by solving we get,
A+B 1 Day work = 2/45,
so A and B together can complete work in 45/2 Days.
Hindu said:
(Sat, Jun 25, 2011 09:32:33 PM)
Hai sheetal your shortcut method helps lot to understand so quickly its really super.
Naveen Kumar said:
(Fri, Jul 1, 2011 01:18:59 AM)
Hi friends, Here is a simple technique to calculate the above problem....
Given,
If the If difference of time is 2 days, B takes 3 days.
If difference of time is 60 days, B takes......?
We can represent the above relation like this,
2------->3
60------>....?
By cross multiplying the above terms we will get... 60*3/2 = 90.
Note:- Always individual term should come in the denominator.
By applying the above procedure you can solve any problem of this type....
I think this technique will help you while doing with this type of problems...
Abdul said:
(Sat, Jul 9, 2011 03:15:31 AM)
Hey Siva your way of solving is fantastic and understandable! Thanks.
Jezan said:
(Sun, Jul 17, 2011 01:04:20 PM)
According to this question if A is x, B will be x+60
1/3=x/x+60
3x=x+60
2x=6
x=30
A+B'S ONE DAY WORK=1/30+1/90=2/45
SO WHOLE WORK S= 45/2( UPSIDE DOWN)
22.5 DAYS.
HOPE ALL LL GET DIS
Jaswinder Singh said:
(Sun, Aug 14, 2011 10:48:44 AM)
Ratio of times taken by A and B = 1 : 3. or 1x:3x
so, we say
3x-1x=60,
2x=60,
x=30, so A will 30 day to complected a work,
B will be complete the work ie 3x, 3(30)=90days,
(A+B) 1 Day work = (1/30 + 1/90)
by solving we get,
A+B 1 Day work = 2/45,
so A and B together can complete work in 45/2 Days.
Sharan said:
(Sun, Aug 21, 2011 11:08:37 PM)
@Jaswinder singh: I understood your explanation man. Thanks.
Sundar said:
(Mon, Aug 22, 2011 11:13:44 AM)
@All (Must read if you have any doubts)
If B takes 3 days then A takes 1 day to complete the task.
Time taken Ratio => A : B = 1 day : 3 days.
1 3 (difference is 2)
10 30 (diff 20)
30 90 (diff 60) <= Here diff is 60 days, So this is the correct ratio to be used in calculation, since it was mentioned in the given question.
A alone can finish the task in 30 days.
B alone can finish the task in 90 days.
Work done by A alone in 1 day = 1/30
Work done by B alone in 1 day = 1/90
Work done by A and B in one day (1/30 + 1/90) = 3+1/90 = 4/90
The no. of days required to complete the task by A and B is
= 90/4
= 22.5 days.
////**** Important Note: ****////
We cannot take other ratios like 1:3, 10:30, 40:120, 60:180 for the calculation. Since the diff is mentioned as 60 days.
Because, it will give different answers for each different ratios used for calculation.
If we take 1:3 => (1/1 + 1/3) = 4/3
If we take 10:30 => (1/10 + 1/30) = 4/30
If we take 40:120 = (1/40 + 1/120) = 4/120
If we take 60:180 => (1/60 + 1/180) = 4/180 ... so on.
I hope this will help you. Have a nice day!
Deepti said:
(Thu, Aug 25, 2011 02:00:08 PM)
It is not so big and easy to understand.
let work done by B in 1 day = 1/x
so work done by A in 1 day = 1/(x-60)
1/(x-60) = 3/x
so x = 3x - 180
x = 90
work done by A and B in 1 day is 30 and 90 respectively
work done by both together in 1 day = 1/30 + 1/90 = 2/45.
total work done = 45/2
Hey its simple to understand.
Days taken by B = x
Days taken by A= x - 60
Their time taken proportio is 1:3
so,
x - 60/ x = 1/3
x=90;
So A will do the work in = 30 days
abd B in 3x= 3*30=90 days,
and u can find their 1 day's work and ad it.
Simple :)
Srinivas said:
(Sun, Sep 25, 2011 10:43:31 AM)
Hi friends,
Given A:B=1:3
Therefore B=3A--------equation 1
let B can do a work in x days.
then A can do the same work in (x-60) days.
then B=3A
x=(x-60)3
therefore x=90 days
therefore B can do a work in 90 days.
and A will do a work in 90-60=30 days.
Pavethra said:
(Thu, Sep 29, 2011 02:15:30 PM)
I tell that A is thrice as good as B so it should be 3:1 na.
Am I right?
Sunil Reddy said:
(Tue, Oct 4, 2011 01:23:52 AM)
We can use a simple formula here:[(KL)/k squqre-1)]
-->here K=3(efficiency),L=60(time) so (3*60/(3*3)-1)=>180/8=221/2
Vinod Reddy said:
(Mon, Nov 7, 2011 02:30:10 PM)
THANK U SHEETAL,your short cut method is simply super.there is no words to say
Sundar said:
(Fri, Nov 18, 2011 08:45:44 AM)
If difference of time is 60 days 3*60/2 = 90 days.
I can't get this step?
Please explain.
Riyaz said:
(Wed, Nov 23, 2011 09:31:52 PM)
Ratio of times taken by A and B = 1 : 3.
That is If A takes 1 day B takes 3 days
Time Difference is 3-1 = 2 days
Here is the tricky part :
If A takes 1/2 day B takes 3/2 days
Time Difference is 3/2 - 1/2 = 1 days
When time difference is 60 days (Just mulitply by 60)
A takes 60/2 and B takes 3*60/2
So, A takes 30 days to do the work.
and B takes 90 days to do the work.
A's 1 day's work = 1/30
B's 1 day's work = 1/90
(A + B)'s 1 day's work = (1/30 + 1/90)= 4/90 = 2/45
A and B together can do the work in 45/2 = 22+1/2
Anu said:
(Sun, Nov 27, 2011 05:05:31 PM)
Awesome explanation HARSHA
Brajesh Anuragi said:
(Mon, Nov 28, 2011 01:13:34 PM)
Thanks Showry for given the simple and correct ans.
Gauarv said:
(Tue, Dec 27, 2011 08:59:05 PM)
Thanks harsha.
Neeraj said:
(Sun, Jan 8, 2012 10:25:01 PM)
A will finish the work 60 days lesser than B.
What is it mean please explain?
Abhay said:
(Tue, Jan 10, 2012 07:49:42 PM)
@Neeraj-A will finish the work 60 days lesser than B,means if B takes 60 days to complete the work,A takes 1 day.
Sureshkumar said:
(Thu, Jan 19, 2012 03:29:49 PM)
Another easy way 2 find out:
1st put the ratio i.e.1:3(A:B)
2nd the condition given here is A can work less than 60 days
So, find out the probability that matches with the ratio condition(A&B must be difference 60 here) for eg:let we take as A as 20 therefore B must be 60(here we get the difference as 40 only)according to 1:3 which cant satisfy
The given condition(A less than B by 60 days) suppose you take A as 30 means you get B as 90 which is greater than 60 days
of A....A=30 B=90 A's 1 day work=1/30
B's 1 day work=1/90 A+B's 1 day work =1/30+1/90=4/90 here they are not given to find out as 1day work...so take as 90/4=22.5 <==> 22(1/2).
Varma said:
(Thu, Jan 26, 2012 05:04:15 PM)
Nice formula @Sheetal.
Aarush said:
(Thu, Feb 16, 2012 02:31:54 PM)
Thanks sheetal.
Raman(Uiet,Kuk) said:
(Fri, Feb 17, 2012 03:33:34 PM)
Guys check this out and don't be confused....
as we know A is 3 time better than B and A takes 60 days less than B so, time taken by A: time taken by B= 1:3
= b-60:b ( suppose time by B is b)
by cross multiply, 3b-180=b
i.e. b=90 so time taken by B=90
and time taken by the A is=90-60= 30
Tabish said:
(Sat, Feb 18, 2012 07:52:25 AM)
@sheetal
do not able to understand how you get that formula to calculate the time i.e.
K*X/K^2-1
Kapil said:
(Mon, Feb 20, 2012 11:13:10 AM)
Nic Explanation. . .Sheethal. . .
Shro said:
(Mon, Feb 20, 2012 09:41:37 PM)
Indhu very easy simple explanation as per the question.
Good :) thanku :)
Sindhu said:
(Thu, Feb 23, 2012 05:20:54 PM)
HI,
This method I feel to be quiet easier.
A is thrice as good as workman as B.
therfore,
A=3B -(1)
finish a job in 60 days less than B
1/B=60+1/A -(2)
i.e B`s One day work = A`s one day work + 60 days.
Solve (1) & (2)
we will get
A= 90;
From (1)
B=A/3
=> B= 30.
(A+B)`s 1 day work = 1/90+1/30
=2/45
=22 1/2 days
Iyappan said:
(Thu, Apr 12, 2012 10:33:40 PM)
Naveen kumar your explanation is beautiful for me.
Sanchi said:
(Sun, Jun 3, 2012 09:59:54 PM)
Very simple way.
3A=1B
B takes x days.
3 (x-60) =x
3x-x=180
X dats is B=90, A=30.
Now,
1/90+1/30=22. 5.
A is thrice as good as workman as B means 1:3(Ratio)
Therefore A is able to finish a job in 60 days less than B
So A= 1/60 and B=1/60 .....(Given)
According to the ratio
A=1/60 B=1/3*60 (As we are calculating by days)
So Now A = 1/60 < B = 1/90 (A finishes work less than B)
Working together, they can do it in:
1/A+B = 1/60 + 1/90 (As we are calculating by days))
1/A+B = 2/45
So
A+B = 45/2 Days
Option (B) is the correct ans
Vidya said:
(Mon, Aug 27, 2012 10:38:17 PM)
Can you please solve this using unitary method. Its b'coz I follow that method.
Anji said:
(Tue, Sep 4, 2012 08:12:43 PM)
Let the time taken by A be x days,
then time taken by B will be 3x days.
Given that,
time taken by A to finish the work = time taken by B -60
i.e, x=3x-60
=> x=30.
Therefore, time taken by A to finish the work is 30 days.
so B takes 90 days.
Now ,work done by A & B in 1 day=1/30 + 1/90
=4/90
=2/45
Time taken by A & B to complete the work=45/2 days
=22 1/2 days
Sanjeev said:
(Tue, Sep 11, 2012 10:01:09 PM)
#include<stdio.h>
void main()
{
float a,b;
int c,d;
printf("enter ratio of A : B\n");
scanf("%f",&a);
printf("enter no of days lesser than B by A to complete work\n");
scanf("%f",&b);
c=ab/(a-1);
d=c-b;
printf("no of days to complete work by A and B is %d",(c*d)/(c+d));
}
Prabha said:
(Mon, Sep 24, 2012 07:00:17 AM)
If difference of time 2 days B takes 3 days
Similarly why don't we take difference of time 60 days B takes 60*3 is 180 days. Please explain to me ?
Joshi Sir said:
(Wed, Nov 21, 2012 07:58:19 PM)
Friends, don't make it complex: Here we go.
Ratio of time taken by A & B = 1:3
And A takes 60 days less then B
Suppose, days taken by B = x then days taken by A = (x - 60)
Thus,
A : B = (x - 60) : x
1 : 3 = (x - 60) : x
1/3 = (x - 60) / x
X = 3 (x - 60)
X = 3x - 180
180 = 3x - x
180 = 2x
X = 180 / 2 = 90
Hence,
Days taken by B = x = 90 days
Days taken by A = (x - 60) = 90 - 60 = 30 days
1 day work of A and B = 1/30 + 1/90
= 4/90
= 2/45
So,
Total days taken by A & B to complete the work = 45/2 = 22.5 days
Ashutosh said:
(Thu, Nov 29, 2012 04:45:15 PM)
Formula-->nx- (n+1) /nx.
4x-4x/3=60 so x=45/2.
Keerthi said:
(Thu, Jan 10, 2013 10:20:09 AM)
So by the explanation above we have to take in the ratio 1:3.
Kavya said:
(Thu, Jan 10, 2013 01:56:00 PM)
A is twice as good a workmen as B and together they can finish a piece of work in 18days. In how many days will A alone finish the work?
Can we solve the above problem using the formula k*x/k^2-1.
Pankaj said:
(Tue, Feb 5, 2013 02:43:08 PM)
Let A takes x days to do the work alone
Therefore days taken by b is (x+60).
Now A is 3 times faster than B
So no.of days taken by A will be 3 times less than B.
So
3*x=(x+60)
2x=60
x=30 days //work done by A
Work done by B=30+60=90 days.
Now we can find work done together
1/30 +1/90 to get the answer.
Monika said:
(Mon, Feb 11, 2013 12:01:32 PM)
We have a direct formula for these kind of questions .. i.e.,
Work done together is given by = (m*d)/(m^2 - 1),
Where d is no of days taken by B and m is no of time A is faster than B,
Therefore = (3*60)/(3^2-1) = 22.5.
Praveen said:
(Sun, Mar 10, 2013 08:08:47 PM)
@All.
Please refer to Sheetal's response as given below. Its the best and easiest way to solve such questions.
PS:Thanks sheetal.
"A is K times as good a worker as B & takes X days less than B to finish the work. Then the amount of time required by A & B working together is K * X / K'S SQUARE - 1.
SO IN QUESTION K IS 3. X IS 60. SO PUTTING THE VALUES IN ABOVE MENTIONED FORMULA.
A and B together can do the work in